The present invention relates to an air-cleaning apparatus and air-cleaning method whereby air is cleaned with an air flow containing ions and ozone generated by corona discharge.
There has been proposed an ozonizer that generates an air flow containing ions and ozone through corona discharge induced by applying a high voltage between electrodes (see Japanese Utility Model Application Post-Examination Publication No. 8-9137). In this ozonizer, a cylindrical electrode and a needle electrode are used. The needle electrode is placed outside one opening of the cylindrical electrode at a predetermined distance therefrom so as to lie approximately in the center of the cylindrical electrode. A high voltage is applied between the two electrodes to generate ions and ozone and also induce an air flow containing ions and ozone that flows out from the other opening of the cylindrical electrode. Thus, the ozonizer induces an ozone-containing air flow and therefore makes it possible to dispense with the need for a motor fan and hence possible to save energy. Furthermore, the ozonizer collects fine dust particles with the electrodes.
However, the above-described conventional ozonizer suffers from various problems. For example, the volume of ozone-containing air generated by the conventional ozonizer is unfavorably small. Therefore, it is difficult for the ozonizer to generate an ozone-containing air flow at a sufficiently high flow rate. Moreover, a high ozone concentration is rather unfavorable for the environment, but the conventional ozonizer cannot reduce the amount of ozone generated. In addition, the conventional ozonizer cannot achieve a satisfactory deodorizing effect. Therefore, a perfume must be used to mask the odor of ozone and strong odors in a room. Furthermore, because fine dust particles are collected with the electrodes, it is necessary to clean the electrodes. When handling the ozonizer to clean the electrodes, great care must be taken because a high voltage is applied between the electrodes.
In view of the above-described circumstances, an object of the present invention is to control the generation of ozone, perform deodorization, sterile filtration and antifungal treatment, and thereby minimize problems attended with ozone.
To attain the above-described object, the present invention provides an air-cleaning apparatus adapted to clean air with an air flow containing ions and ozone generated by corona discharge. The air-cleaning apparatus has a wind tunnel part including a trumpet-shaped member having an opening at a bottom thereof and a cylindrical member connected to the opening at the bottom of the trumpet-shaped member. The wind tunnel part has a titanium dioxide metal evaporated onto the surface thereof. A needle electrode is placed in front of the trumpet-shaped member of the wind tunnel part near an axis of the trumpet-shaped member. An annular electrode is formed on the wind tunnel part. The air-cleaning apparatus further has a high-voltage generating unit that applies a high voltage between the needle electrode and the annular electrode. Corona discharge is induced by applying the high voltage between the needle electrode and the annular electrode, thereby generating an air flow containing ions and ozone that flows from the trumpet-shaped member toward the cylindrical member, and thus cleaning air.
The wind tunnel part has the annular electrode formed from the whole or part of the trumpet-shaped member. The needle electrode includes a plurality of needle electrodes placed on an axis of the wind tunnel part or near the axis. A guide wire having titanium dioxide evaporated thereonto is placed at an opening of the cylindrical member on a side thereof remote from the trumpet-shaped member. A housing accommodates the needle electrode, the annular electrode and the wind tunnel part, together with a plate having titanium dioxide or/and zinc oxide evaporated thereonto. The housing has an air inlet provided on a side thereof closer to the needle electrode. The housing further has an air outlet provided on a side thereof closer to the cylindrical member of the wind tunnel part. The housing has an inner wall surface coated with an amorphous metal of copper, nickel and phosphorus and a ceramic powder of aluminum oxide. The housing has a titanium dioxide-evaporated plate provided near the inner wall thereof. Another titanium dioxide-evaporated plate is provided near the air inlet. The housing may be a part of an air-conditioning duct.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.